Republicans hoping to unseat Gov. Mark Dayton and U.S. Sen. Al Franken are crisscrossing the state, hitting county fairs, parades, rallies and phone banks in a last-minute scramble to win over primary voters, who on Tuesday will choose the candidates to carry the party's message in November.

Turnout is projected to be low for the late-summer primary, possibly between 200,000 and 300,000, according to the secretary of state. That's a sharp contrast with 2010, when a high-profile primary that featured Dayton against the DFL's endorsee and others brought more than 442,000 Minnesotans to the polls. This time, as few as 50,000 votes statewide could determine which Republican takes on Dayton.

"We have four, I think, really strong candidates, all of whom would be a very welcome change from Mark Dayton," said Keith Downey, chairman of the Minnesota Republican Party. "When someone advances, it will be their job to paint our vision for the state, and what Mark Dayton and one-party DFL rule has meant in St. Paul."

For the state GOP, Tuesday's stakes are high. The right candidates could help it ride a Republican wave predicted nationally and break a yearslong losing streak. Minnesota Republicans have not won a statewide race since 2006. They lost control of the House and Senate in 2012 and no longer hold any constitutional offices or either U.S. Senate seat.

The party believes its best chance in the Senate race is Mike McFadden, an independently wealthy businessman, a first-time candidate who secured the party's endorsement over a field of more experienced candidates. He's raised enough money to mount a serious campaign aimed mostly at Franken. McFadden has a primary challenge from state Rep. Jim Abeler, R-Anoka, and others, but has largely ignored them.

In the governor's race, Hennepin County Commissioner Jeff Johnson, Rep. Kurt Zellers, former Rep. Marty Seifert and businessman Scott Honour have waged a low-key primary from which no clear favorite emerged. Johnson is thought to have some advantage because he carries the party's endorsement. Merrill Anderson, a retired executive, is also on the ballot.

DFL leaders who thought their top incumbents would run unchallenged were startled when former Rep. Matt Entenza resurfaced this election season to challenge state Auditor Rebecca Otto in a bid to restart his political career. Entenza ran and lost in 2010's gubernatorial primary.

That squabble aside, Democrats are hoping positive economic trends in Minnesota will be a barrier against Republican gains in the coming general election.

Even some prominent Republicans foresee a tough slog for whoever tries to unseat Dayton over pocketbook issues.

"The economy is pretty strong," said Charlie Weaver, a veteran of state Republican politics and executive director of the Minnesota Business Partnership, which represents the state's largest corporations. "We have a low unemployment rate — one of the lowest in the country," he said.

A former top aide under Gov. Tim Pawlenty, Weaver predicted that Republican candidates, particularly Dayton's challenger, will be forced to find other issues as contrasts with Democrats.

Weaver is publicly neutral in the GOP gubernatorial primary, as is the partnership.

Despite a crowded gubernatorial primary field, many Republicans viewed the four candidates as somewhat interchangeable.

"There isn't anybody who's obviously caught fire and has the bandwagon going full steam ahead," said Ron Carey, who chaired the state Republican Party from 2005 to 2009. "These are four good guys that are philosophically close to each other."

Carey said he is backing Johnson. "The endorsement can be a tiebreaker for a lot of people," he said.

By the end of last week, Johnson was drawing barbs from both Honour and Zellers, prompting him to suggest himself as front-runner. State GOP chief Downey said some internal party indicators suggest Johnson has pulled ahead at least a little.

Downey said that endorsement or not, the party will embrace whoever wins Tuesday. The party is not hosting a victory celebration for its slate Tuesday but instead plans to have leaders rush to the election night party of whichever candidate comes out on top.

Downey's counterpart, state DFL Chairman Ken Martin, said his party is eager for the governor's race to come into focus.

"The reality is it doesn't matter which of the four come out," Martin said. "I think the contrast is pretty stark between the governor and any of the four, and we're eager to start drawing that contrast."

While the governor's race has remained muddled, the U.S. Senate contest has followed a more conventional path. Sitting comfortably as front-runner, McFadden largely steered clear of specific issues as he sought to instead to capitalize on anti-Washington sentiment by running as a political outsider.

McFadden may have suffered a self-inflicted wound last week, when in his support for the Keystone Pipeline he said he would opt for building it with Chinese steel over U.S. steel if the import was cheaper. That prompted tirades from union activists on an issue of sensitivity to Minnesota's Iron Range; McFadden said he places a high value on being "cost competitive" on projects that use taxpayer money.

Abeler has run a classic underdog campaign, winning endorsements from the likes of former U.S. Sen. David Durenberger and former Republican Gov. Al Quie and emphasizing a legislative career that earned bipartisan respect. But his fundraising has lagged. That's a major strike against him, for many Republicans are aware of Franken's formidable fundraising operation.

Congressional challenges

In the Sixth District, former state Rep. Tom Emmer is trying for a comeback after his 2010 defeat at Dayton's hands in the governor's race. The Delano Republican is positioned as the likeliest Republican heir to the retiring Michele Bachmann, but faces a spirited challenge from Rhonda Sivarajah, an Anoka County commissioner. Whoever emerges will face DFLer Joe Perske, the mayor of Sartell.

In the First District, endorsed GOP candidate Aaron Miller, a military veteran and businessman from Byron, is getting a stiff challenge from Blue Earth businessman Jim Hagedorn, who has armed himself with a raft of legislative supporters. The winner faces U.S. Rep. Tim Walz, seeking his fifth term.

Martin said the party is already gearing up for the general election but is mindful of special contests such as Otto/Entenza. There, Martin has not been shy about pouring the party's resources into protecting the incumbent, including door-knocking, direct mail and help with radio and TV ads. Entenza has countered, pumping more than $670,000 of his own money into his campaign.

Martin said he is confident Otto will prevail.

"We're making sure that as we go into the fall election, we have a unified ticket with no distractions on the ballot," he said.

Patrick Condon • 651-925-5049